Im thinking about getting a GL80 tent. Its 3' x 3' x 5'. I want to grow 4 full size plants in it. Im hoping to get 8 ounces each harvest atleast. I dont want to have to have separate cooling for the hood though. I want the ballast to be able to switch HPS and Mh as well. Should I do a 400W or a 250W? Im going to have a 4" vortex exhaust fan with a carbon filter. Not sure if it will be passive or another fan for intake. Any advice?